JPH08292557A - Photosensitive planographic printing plate and its production - Google Patents

Abstract

PURPOSE: To provide a photosensitive planographic printing plate having a wide range for proper developing conditions, no deterioration in the film strength, enough printing durability and high sensitivity. CONSTITUTION: This photosensitive planographic printing plate has at least one photosensitive layer containing an o-quinone diazide compd. and an alkali- soluble resin on a supporting body. In the photosensitive layer, the max. concn. of the o-quinone diazide compd. is at the position with a distance more than 1/2 of the film thickness from the supporting body side. The photosensitive planographic printing plate is produced by dissolving a photosensitive compsn. containing an o-quinone diazide compd. and an alkali-soluble resin in a mixture solvent of a good solvent having a low boiling temp. and a bad solvent having a high boiling temp. for the o-quinone diazide compd. to prepare a coating liquid, then applying the coating liquid and drying under at least two different temp. conditions.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION A photosensitive lithographic printing plate is one in which a photosensitive layer is provided on a hydrophilic support. For example, in a positive type photosensitive lithographic printing plate, an actinic ray such as ultraviolet rays is provided on the hydrophilic support. An ink-receptive photosensitive layer that is solubilized by exposure to is formed.

In such a positive-working photosensitive lithographic printing plate, when the photosensitive layer is imagewise exposed and then developed, the ink-receptive photosensitive layer in the exposed area is removed to expose the surface of the hydrophilic support. On the other hand, the unexposed portion of the photosensitive layer which is ink-receptive remains on the support to form an ink-receptive layer. In lithographic printing, the difference in the property that the exposed portion is hydrophilic and the unexposed portion is lipophilic is used.

Usually, the photosensitive layer of a positive-working photosensitive lithographic printing plate contains a photosensitive composition containing an o-quinonediazide compound as a photosensitive component and an alkali-soluble resin as a component for enhancing film strength and alkali solubility. Things are used.

The most typical example of these photosensitive compositions is a photosensitive composition using trihydroxybenzophenone-1,2-naphthoquinone diazide sulfonic acid ester and cresol formaldehyde novolak resin, which is Thompson "Introduction to Micro". Lithography ”(ACS Publication, No. 219, p112-121), and U.S. Pat. No. 3,666,473.
U.S. Pat.No. 4,115,128 and U.S. Pat.No. 4,173,470
In the specification and the like, a compound having a naphthoquinonediazide-substituted compound and a novolak-type phenol resin which is an alkali-soluble resin is described. In addition, a photosensitive composition containing many naphthoquinonediazide compounds and an alkali-soluble resin has been proposed and put into practical use.

Since the orthoquinonediazide compound produces a carboxylic acid upon irradiation with an actinic ray and becomes soluble in an alkaline aqueous solution, a photosensitive composition containing these naphthoquinonediazide compound and an alkali-soluble resin was used by utilizing this property. For the plate making process of the positive photosensitive lithographic printing plate,
An aqueous alkaline developer is used.

In order to enhance the developability of the photosensitive lithographic printing plate, it is necessary to enhance the alkali solubility of the photosensitive composition. As a method of enhancing the alkali solubility, an alkali-soluble resin that reduces the molecular weight of the naphthoquinonediazide photosensitive material is used. There are known methods such as decreasing the molecular weight of, reducing the amount of the photosensitive material in the photosensitive layer, and adding an organic acid, an inorganic acid, or an acid anhydride. However, problems such as a decrease in printing durability and a narrow range of appropriate developing conditions occur.

Further, JP-A-58-205154 discloses, as a photosensitive lithographic printing plate which solves the above problems, a support is provided with a photosensitive layer consisting of an upper layer and a lower layer, and an o-quinonediazide compound in the upper layer is prepared. A photosensitive lithographic printing plate is described in which the content is higher than the content of the o-quinonediazide compound in the lower layer. Although this photosensitive lithographic printing plate certainly solves some of the above problems,
It is not sufficient, and since it is essential to form the upper layer and the lower layer, the production process is complicated and the production cost is inevitably increased.

Then, the inventors of the present invention investigated and found that the concentration distribution of the o-quinonediazide compound in the photosensitive layer was
It has been found that the above problem can be solved by making the maximum concentration of the o-quinonediazide compound at a position farther than 1/2 of the film thickness of the photosensitive layer when viewed from the support side.

[0010]

Accordingly, an object of the present invention is to provide a photosensitive lithographic printing plate having a wide range of suitable developing conditions, having no deterioration in film strength, having sufficient printing durability, and having high sensitivity. It is to provide a method for producing the photosensitive lithographic printing plate.

[0011]

The above objects of the present invention are as follows: (1) The maximum concentration of the o-quinonediazide compound in the support is at a position farther than 1/2 of the thickness of the photosensitive layer as viewed from the support side. A photosensitive lithographic printing plate comprising at least one photosensitive layer containing a quinonediazide compound and an alkali-soluble resin. (2) The photosensitive lithographic printing plate as described in (1) above, wherein the number of the photosensitive layers containing the o-quinonediazide compound and the alkali-soluble resin provided on the support is one. (3) The support is coated with a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble resin,
-A coating solution dissolved in a mixed solvent consisting of a good solvent for a quinonediazide compound and a poor solvent for an o-quinonediazide compound having a high boiling point is applied and dried under at least two or more different temperature conditions. 1) The method for producing a photosensitive lithographic printing plate as described in 2). (4) The method for producing a photosensitive lithographic printing plate as described in (3) above, wherein the drying is performed at a low temperature in the initial stage and then the drying is performed at a high temperature. Can be achieved by

First, the support used for forming the photosensitive lithographic printing plate of the present invention will be described.

The support preferably has flexibility so that it can be set in an ordinary printing machine and can withstand a load applied during printing. For example, a metal plate of aluminum, magnesium, zinc, chromium, iron, copper, nickel or the like, An alloy plate of these metals, or a metal plate coated with chromium, zinc, copper, nickel, aluminum, iron or the like by plating or vapor deposition can be used. Of these, the support is preferably one using aluminum or its alloy.

Various kinds of aluminum alloys can be used, for example, silicon, copper, manganese, magnesium,
Examples include alloys of metals such as chromium, zinc, lead, bismuth, and nickel with aluminum.

The support made of aluminum or its alloy is usually subjected to a degreasing treatment prior to the graining treatment in order to remove oil and fat components such as rolling oil adhering to the surface of the support. As the degreasing treatment, degreasing treatment using a solvent such as trichlene and thinner, emulsion degreasing treatment using an emulsion of kesilon and triethanol, and the like are used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, it is possible to remove stains and oxide films which cannot be removed only by the above degreasing treatment.

The graining treatment of the present invention is a so-called mechanical surface-roughening method for mechanically roughening the surface, a so-called chemical surface-roughening method for chemically selectively surface-melting and roughening the surface, and electrochemical. The surface can be roughened by a known method such as a so-called electrochemical roughening method.

Mechanical surface roughening methods include, for example, ball polishing, brush polishing, blast polishing, buff polishing, and the like, and electrochemical surface roughening methods include hydrochloric acid, nitric acid, etc. There is a method of electrolytically treating with an alternating current or a direct current in an electrolytic solution containing the same.

The graining treatment of the present invention can be carried out by any one of these methods or by using two or more methods in combination.

Since smut is produced on the surface of the support obtained by the graining treatment, it is generally preferable to appropriately perform washing with water or alkali etching in order to remove the smut. Examples of such a treatment include a treatment method such as an alkali etching method described in JP-B-48-28123 and a sulfuric acid desmutting method described in JP-A-53-12739.

The support treated as described above is then anodized. Wear resistance due to anodizing treatment,
The chemical resistance and water retention can be improved. A known method can be used for the anodizing treatment. For example, a method of electrolyzing at a current density of 1 to 10 A / dm ² using an aqueous solution containing sulfuric acid and / or phosphoric acid at a concentration of 10 to 50% is used. Although preferably used, a method of electrolyzing at a high current density in sulfuric acid described in other U.S. Pat.No. 1,412,768, or a method of electrolyzing using phosphoric acid described in U.S. Pat.No. 3,511,661. Etc. can also be used.

The anodized support may be subjected to a pore-sealing treatment, if necessary. These sealing treatments can be carried out by using known methods such as hot water treatment, boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment and ammonium acetate treatment.

The support is preferably provided with a hydrophilic layer. For the formation of the hydrophilic layer, a water-soluble polymer, an alkali metal silicate described in US Pat. No. 3,181,461,
Amino acids and salts thereof described in JP-A-60-149491 and JP-A-63-165183, amines having a hydroxyl group and salts thereof described in JP-A-60-232998, JP-A-62- 1
Although it is possible to use a phosphate described in 9494, a polymer compound containing a monomer unit having a sulfo group described in JP-A-59-101651, etc., the following compounds are used in the present invention. Is preferred. Water-soluble polymer Specific examples thereof include vinyl resins such as PVA (polyvinyl alcohol), modified PVA, PVPA (polyvinylphosphonic acid), polyvinylpyrrolidone, polyvinylimidazoline and the like; polyacrylic acid, polyacrylamide, polyhydroxyethyl acrylate. Acrylic acid-based copolymers such as; polyethyleneimine; maleic acid copolymers; polyethylene glycol; polypropylene glycol; polyurethane resin; polyhydroxymethylurea;
Polyhydroxymethyl melamine resin; soluble starch;
CMC (carboxymethyl cellulose); hydroxyethyl cellulose; guar gum; tragacanth gum; xanthan gum; sodium alginate; gelatin and the like. At least one amino group and two or more

[0023]

Embedded image A compound having a group selected from the following or a salt thereof: Examples of the compound having a phosphonic acid group or a salt thereof include 1-aminoethane-1,1-diphosphonic acid and 1-amino-1-phenylmethane-1,1. -Diphosphonic acid, 1-dimethylaminoethane-1,1-diphosphonic acid, 1-dimethylaminobutane-1,1-diphosphonic acid, 1-dimethylaminomethane-1,1-diphosphonic acid, 1-propylaminoethane-1 , 1-diphosphonic acid, 1-butylaminomethane-1,1-diphosphonic acid,
Aminotrimethylenephosphonic acid, ethylenediaminopentamethylenephosphonic acid, ethylenediaminotetramethylenephosphonic acid, diethylenetriaminopentamethylenephosphonic acid, aminotri (2-propylene-2-phosphonic acid) and hydrochlorides, formates, and oxalates of these compounds Examples of the compound having a phosphinic acid group or a salt thereof include a compound in which the phosphonic acid group of the compound having a phosphonic acid group is changed to a phosphinic acid group, or a salt of these compounds, for example, aminotrimethylene. Phosphinic acid and the like, and as the compound having a phosphoric acid group or a salt thereof, a compound in which the phosphonic acid group of the compound having a phosphonic acid group is changed to a phosphoric acid group or a salt of these compounds,
For example, aminotrimethylene phosphoric acid and the like can be mentioned. A compound having at least one amino group and a carboxyl group or a sulfone group or a salt thereof, specific examples thereof include aminoacetic acid, lysine, threonine, serine, aspartic acid, parahydroxyphenylglycine, dihydroxyethylglycine, anthranilic acid, tryptophan, Examples include amino acids such as arginine, aliphatic amino sulfonic acids such as sulfamic acid and cyclohexyl sulfamic acid, and hydrochlorides, formates and oxalates of these compounds. Compounds having at least one amino group and at least one hydroxyl group or salts thereof. Specific examples thereof include monoethanolamine, diethanolamine, trimethanolamine, tripropanolamine, triethanolamine and hydrochlorides and formates of these compounds. , Oxalate and the like. Alkanes having at least two amino groups or salts thereof Alkanes include linear, branched, and cyclic ones.

Particularly preferred is NH _2- (CH ₂ ) _n
Is -NH ₂ (n is an integer of 2 to 10).

As a specific example, ethylenediamine, 1,
3-diaminopropane, 1,4-diaminobutane, 1,
2-diaminopropane, 1,2-diamino-2-methylpropane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,2-diaminocyclohexane, 1,8-diaminooctane , 1,
Examples include 9-diaminononane, 1,10-diaminodecane and their compounds such as hydrochlorides, formates and oxalates.

Next, the o-quinonediazide compound and the alkali-soluble resin used in the photosensitive layer of the photosensitive lithographic printing plate of the present invention will be described.

The o-quinonediazide compound used in the photosensitive layer of the present invention is a compound having an o-quinonediazide group in the molecule and can be used in the present invention.
The quinonediazide compound is not particularly limited, and examples thereof include polycondensation resins having an orthoquinonediazide group, such as ester compounds of polycondensation resins of o-naphthoquinonediazide sulfonic acid and phenols and aldehydes or ketones. To be

Examples of the phenols in the polycondensation resin of the above-mentioned phenols and aldehydes or ketones include phenol, o-cresol, m-cresol,
Examples include monohydric phenols such as p-cresol, 3,5-xylenol, carvacrol, thymol, dihydric phenols such as catechol, resorcin, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde,
Examples thereof include benzaldehyde, acetaldehyde, crotonaldehyde, furfural and the like. Of these, preferred are formaldehyde and benzaldehyde. Examples of ketones include acetone and methyl ethyl ketone.

Specific examples of polycondensation resins with phenols and aldehydes or ketones include phenol-formaldehyde resin, m-cresol-formaldehyde resin, m- and p-mixed cresol-formaldehyde resin, resorcin-benzaldehyde resin, Examples include pyrogallol / acetone resin.

In the o-naphthoquinonediazide compound, the condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH groups of phenols (reaction rate with respect to one OH group) is preferably 15% to 80%, more preferably 20%. ~
45%.

Further, as the orthoquinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be mentioned. That is, for example, 1,
2-benzoquinone diazide sulfonate, 1,2
-Naphthoquinone diazide sulfonate, 1,2-
Well-known 1,2 such as benzoquinone diazide sulfonic acid amide and 1,2-naphthoquinone diazide sulfonic acid amide
-Quinonediazide compounds, more specifically J. Kosar, "Light-Sensitive Systems," pages 339-352 (196).
5 years), John Willy & Sons
ey & Sons) (New York) and W.S.
1,2-Benzoquinonediazide-4-sulfonic acid phenyl ester described in "Photoresist", Volume 50 (1975) by McDeraw Hill, New York, by WS De Forest. , 1,2,1 ', 2'-di- (benzoquinonediazide-4-sulfonyl) -dihydroxybiphenyl, 1,2-benzoquinonediazide-4- (N-ethyl-N-β-naphthyl) -sulfonamide, 1 , 2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1- (1,2-naphthoquinonediazide-5-sulfonyl) -3,5-dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfonic acid-4'- Hydroxydiphenyl-4'-azo-β-naphthol ester,
N, N-di- (1,2-naphthoquinonediazide-5-sulfonyl) -aniline, 2 '-(1,2-naphthoquinonediazide-5-sulfonyloxy) -1-hydroxy-
Anthraquinone, 1,2-naphthoquinonediazide-5
Sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 2 mol and 4 , 4'-Diaminobenzophenone condensate with 1 mol, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 2 mol and 4,4'-dihydroxy-
A condensation product with 1 mol of 1,1′-diphenylsulfonic acid,
1,2-naphthoquinonediazide-5-sulfonic acid chloride 1 mol condensate with purpurogallin 1 mol, 1,2-
A 1,2-quinonediazide compound such as naphthoquinonediazide-5- (N-dihydroabietyl) -sulfonamide can be exemplified. In addition, Japanese Patent Publication 37-1953
No. 37, No. 37-3627, No. 37-13109, No. 40-26126, No. 40-
No. 3801, No. 45-5604, No. 45-27345, No. 51-13013,
The 1,2-quinonediazide compounds described in JP-A-48-96575, JP-A-48-63802 and JP-A-48-63803 can also be mentioned.

Of the above orthoquinonediazide compounds,
An o-quinone diazide ester compound obtained by reacting 1,2-benzoquinone diazide sulfonyl chloride or 1,2-naphthoquinone diazide sulfonyl chloride with pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferable.

Next, the alkali-soluble resin will be described.

The alkali-soluble resin that can be used in the present invention is not particularly limited, and examples thereof include novolac resins, vinyl polymers having phenolic hydroxyl groups, and those described in JP-A-55-57841. Examples thereof include condensation resins of polyphenols with aldehydes or ketones.

Examples of the novolac resin that can be used in the present invention include phenol / formaldehyde resin, cresol / formaldehyde resin, JP-A-55-5.
Phenol / cresol / formaldehyde copolymer resin as described in Japanese Patent No. 7841, JP-A-55-12755
Examples thereof include copolymer resins of p-substituted phenol and phenol or cresol and formaldehyde as described in JP-A-3.

The molecular weight (polystyrene standard) of the novolac resin is preferably such that the number average molecular weight Mn is 3.00 × 10 ^{2 to} 7.5.
0 × 10 ³ , weight average molecular weight Mw of 1.00 × 10 ^{3 to} 3.00 × 10 ⁴ ,
More preferably, Mn is 5.00 × 10 ^{2 to} 4.00 × 10 ³ , and Mw is 3.
It is 00 × 10 ^{3 to} 2.00 × 10 ⁴ .

The above novolak resins may be used alone or in combination of two or more kinds.

The novolac resin is contained in the photosensitive composition in an amount of 5 to 95.
It is preferable to contain it by weight percent.

The vinyl polymer having a phenolic hydroxyl group is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and is represented by the following general formula [I] to
A polymer containing at least one structural unit represented by [V] is preferable.

[0040]

Embedded image

In the general formulas [I] to [V], R
₁ and R ₂ each represent a hydrogen atom, an alkyl group or a carboxyl group, and preferably a hydrogen atom. R
₃ represents a hydrogen atom, a halogen atom or an alkyl group,
Preferred is a hydrogen atom or an alkyl group such as a methyl group and an ethyl group. R ₄ and R ₅ represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom. A represents an optionally substituted alkylene group that connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B represents a substituent. Represents a phenylene group which may be substituted or a naphthylene group which may have a substituent.

The vinyl polymer having a phenolic hydroxyl group used in the present invention preferably has a copolymer type structure having the structural units represented by the above general formulas [I] to [V]. As the monomer to be copolymerized,
For example, ethylene, propylene, isobutylene, butadiene, isoprene and other ethylenically unsaturated olefins,
For example, styrenes such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene, for example,
Acrylic acids such as acrylic acid and methacrylic acid, for example,
Itaconic acid, maleic acid, unsaturated aliphatic dicarboxylic acids such as maleic anhydride, for example, methyl acrylate, ethyl acrylate, acrylate n-butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, Phenyl acrylate, α-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, esters of α-methylene aliphatic monocarboxylic acid such as ethyl ethacrylate, for example, acrylonitrile, nitriles such as methacrylonitrile, for example, acrylamide. Amides such as, for example, acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-
Anilides such as methoxyacrylanilide, for example, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl esters such as vinyl acetate, for example, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, vinyl ethers such as β-chloroethyl vinyl ether, Vinyl chloride, vinylidene chloride, vinylidene cyanide, for example, 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-nitro Ethylene derivatives such as ethylene, for example, N-vinyl-based monomers such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene and N-vinylpyrrolidone. These monomers are present in the polymer compound in a structure in which the unsaturated double bond is cleaved.

Of the above monomers, aliphatic monocarboxylic acid esters and nitriles are preferable because they exhibit excellent performance for the purpose of the present invention.

These monomers may be bonded to the polymer used in the present invention in either a block or random state.

The vinyl polymer having a phenolic hydroxyl group is preferably contained in the photosensitive composition in an amount of 0.5 to 70% by weight.

As the vinyl polymer having a phenolic hydroxyl group, the above polymers may be used alone or in combination of two or more kinds. It can also be used in combination with other polymer compounds.

Further, a printout material capable of forming a visible image upon exposure can be added to the photosensitive layer of the present invention. The printout material is composed of a compound that generates an acid or a free radical upon exposure to light and an organic dye that changes its color tone by interacting with the generated acid or a free radical. Examples of the compound include o-naphthoquinonediazide-4-sulfonic acid halogenide described in JP-A-50-36209, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-53-36223. , JP Sho
O-6-naphthoquinonediazide-4 described in JP-A-55-6244
-Ester compound or amide compound of sulfonic acid chloride and phenol or aniline having an electron-withdrawing substituent, JP-A-55-77742, JP-A-57-148784
Examples thereof include halomethylvinyloxadiazole compounds and diazonium salts described in JP-A No.
Examples of organic dyes include Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), and Oil Blue # 603.
(Manufactured by Orient Chemical Industry Co., Ltd.), Sudan Blue II
(Manufactured by BASF), crystal violet, malachite green, fuchsin, methyl violet, ethyl violet, methyl orange, brilliant green, congo red, eosin, rhodamine 66 and the like.

In addition to the above-mentioned materials, a plasticizer, a surfactant, an organic acid, an acid anhydride and the like can be added to the photosensitive layer of the present invention, if necessary.

Further, in order to improve the oil sensitivity of the photosensitive layer, for example, p-tert-butylphenolformaldehyde resin, pn-octylphenolformaldehyde resin or these resins may be added to the photosensitive layer of the present invention.
A resin partially esterified with a quinonediazide compound may be added.

The photosensitive layer of the present invention can be formed by coating a support with a coating solution prepared by dissolving or dispersing a photosensitive composition comprising these components in a solvent and drying it.

The coating method used for coating the photosensitive layer coating liquid on the support surface is a conventionally known method, for example, spin coating, wire bar coating, dip coating, air knife coating, spray coating, air spray coating, Methods such as electrostatic air spray coating, roll coating, blade coating and curtain coating are used.

The maximum concentration of the o-quinonediazide compound in the photosensitive layer of the present invention is, when viewed from the side of the support, 1 of the film thickness of the photosensitive layer.
The photosensitive layer containing an o-quinonediazide compound and an alkali-soluble resin (hereinafter referred to as the photosensitive layer of the present invention) at a position farther than / 2 is, for example, a photosensitive composition containing a good o-quinonediazide compound having a low boiling point. Solvent and high boiling point o
It is formed by applying a coating solution dissolved in a mixed solvent composed of a poor solvent of a quinonediazide compound and drying at least two or more different temperature conditions.

In the present invention, when a plurality of photosensitive layers are provided, the photosensitive layer on the outermost surface is preferably the photosensitive layer of the present invention. Further, some or all of the plurality of photosensitive layers may be the photosensitive layer of the present invention.

The maximum concentration of the o-quinonediazide compound in the photosensitive layer of the present invention is preferably at or near the surface.

The good solvent and the poor solvent are relative ones and are not particularly limited, but as a good solvent for the o-quinonediazide compound, 5% by weight or more of the o-quinonediazide compound is dissolved at room temperature. Is used, and the o-quinonediazide compound is used as a poor solvent for the o-quinonediazide compound at room temperature.
It is preferable to use a solvent that can dissolve less than wt%. The difference between the boiling points of the good solvent and the poor solvent is preferably 20 ° C or higher, and more preferably 30 ° C or higher.

A photosensitive composition was dissolved in a mixed solvent consisting of a good solvent of an o-quinonediazide compound having a low boiling point and a poor solvent of an o-quinonediazide compound having a high boiling point to apply a coating solution, and at least two different compositions were applied. By drying under the temperature condition, o
-Whether the photosensitive layer having the maximum concentration of the quinonediazide compound is formed is not clear, but the photosensitive composition may be used as a good solvent for the o-quinonediazide compound having a low boiling point and as a high boiling point o-.
When a coating solution dissolved in a mixed solvent consisting of a poor solvent of a quinonediazide compound is applied and dried, first a good solvent with a low boiling point and fast evaporation is evaporated from the surface, and the content ratio of the poor solvent on the surface of the photosensitive layer increases, Along with that, an o-quinonediazide compound is deposited, and a solution containing the o-quinonediazide compound is diffused from there to the lower layer, and further evaporation of the solvent is performed, so that a large amount of the o-quinonediazide compound exists on the surface side of the photosensitive layer. It is believed that the above results can be obtained by performing the drying under at least two or more different temperature conditions.

A poor solvent and a good solvent are relatively determined, and a high boiling point and a low boiling point are relatively determined, and what is meant by a poor solvent of an o-quinonediazide compound having a high boiling point is a solvent.
In addition, it is not possible to clearly show the range of how a good solvent for a low boiling point o-quinonediazide compound refers to a solvent, but a good solvent for a low boiling point o-quinonediazide compound used in the present invention is Examples of the poor solvent for the high o-quinonediazide compound include the following.

In practice, in the present invention, a poor solvent for the o-quinonediazide compound having a high boiling point and a good solvent for the o-quinonediazide compound having a low boiling point may be selected and used. Examples of poor solvents for o-quinonediazide compounds having high boiling points Propylene glycol alkyl ethers (eg, propylene glycol monomethyl ether, propylene glycol monoethyl ether), dipropylene glycol alkyl ethers (eg, dipropylene glycol monomethyl ether, dipropylene glycol) Monoethyl ether), diethylene glycols [eg, dimethyl carbitol (DMDG), diethyl carbitol (DEDG), methyl carbitol], alcohols (eg, pentanol, hexanol, 3-methoxy-1-butanol), methylpropyl Ketone, methyl butyl ketone, diacetone alcohol, cyclopentanone, cyclohexanone. Examples of good solvents for o-quinonediazide compounds having low boiling points Acetone, methyl ethyl ketone, 4-hydroxy-2-
Butanone, methyl lactate, cellosolves (eg methyl cellosolve, ethyl cellosolve).

The photosensitive layer of the present invention is dried under at least two or more different temperature conditions, but it is preferable to perform drying at a low temperature and then at a high temperature in the initial stage of drying. Examples of these drying conditions include the following drying conditions. The combination of drying conditions can be selected by conducting a simple experiment. -Drying conditions of the photosensitive layer Conditions: Temperature: 20 ° C to 60 ° C, preferably 25 ° C to 55 ° C Time: 10 seconds to 120 seconds, preferably 15 seconds to 110 seconds Conditions Temperature: 45 ° C to 90 ° C, preferably 50 ° C ~ 85 ° C time; 10 seconds to 120 seconds, preferably 15 seconds to 110 seconds Conditions temperature; 70 ° C to 150 ° C, preferably 65 ° C to 145 ° C time; 10 seconds to 120 seconds, preferably 15 seconds to 110 seconds Conditions Temperature: 150 ° C. to time: 10 seconds to 120 seconds, preferably 15 seconds to 110 seconds The coating amount of the photosensitive layer coating solution is 0.
5 μm to 8.0 μm is preferable, and 1.0 μm to 4.0 μm is more preferable.

The proportion of the o-quinonediazide compound in the photosensitive layer is preferably 5 to 60% by weight, and particularly preferably 10 to 50% by weight.

In the photosensitive lithographic printing plate of the present invention, the photosensitive layer may have two or more layers.

Further, o- used in each photosensitive layer
The quinonediazide compounds may be the same or different, and more than one o-quinonediazide compound may be present in each layer.

In the case of having two or more photosensitive layers, at least one of the photosensitive layers may be the photosensitive layer of the present invention, and the other photosensitive layer may be the photosensitive layer of the present invention. It may be a photosensitive layer.

The proportion of the o-quinonediazide compound in the photosensitive layer is preferably large in the surface layer.

At this time, the coating amount of the coating solution for the photosensitive layer is preferably 0.5 μm to 8.0 μm, more preferably 1.0 μm to 4.0 μm as the dry film thickness of the photosensitive layer.

The positive-working photosensitive lithographic printing plate of the present invention can be made into a plate by exposing and developing it in a usual manner. For example, a transparent original image having a line image, a halftone dot image and the like is exposed in close contact with the photosensitive surface, and then the photosensitive layer in the non-image area is removed using an appropriate developing solution to obtain a relief image. To be

Suitable light sources for exposure include mercury lamps, metal halide lamps, xenon lamps, chemical lamps,
Examples include carbon arc lamps. Further, as the developing solution and the developing replenishing solution used for the development, an alkaline aqueous solution is preferable, and examples thereof include alkali metal silicates such as sodium silicate and potassium silicate, sodium hydroxide, potassium hydroxide, trisodium phosphate, An alkaline aqueous solution such as an aqueous solution of sodium diphosphate, sodium carbonate, potassium carbonate or the like can be used.

In the present invention, the developer and the replenisher for development used for developing the photosensitive lithographic printing plate are preferably those containing an alkali metal silicate. The alkali metal of the alkali metal silicate includes lithium, sodium and potassium, and potassium is the most preferable.

At the time of development, it is preferable that the development replenisher is appropriately replenished in accordance with the development processing amount of the photosensitive lithographic printing plate.

The preferred developing solution and developing replenishing solution are [SiO 2
₂ ] / [M] (wherein [SiO ₂ ] represents the molar concentration of SiO ₂ and [M] represents the molar concentration of alkali metal).
15 to 1.0, and the SiO ₂ concentration is 0.5 to 5.0 with respect to the total weight.
It is an aqueous solution of an alkali metal silicate which is wt%. Further, particularly preferably, [SiO ₂ ] / [M] of the developer is
0.25 to 0.75, the SiO ₂ concentration is 1.0 to 4.0% by weight, the development replenisher [SiO ₂ ] / [M] is 0.15 to 0.5, and S
The iO ₂ concentration is 1.0 to 3.0% by weight.

The pH of the developing solution and the developing replenisher is preferably
12 to 13.8.

The above-mentioned developers and development replenishers may contain water-soluble or alkali-soluble organic and inorganic reducing agents.

Examples of the organic reducing agent include phenol compounds such as hydroquinone, metol and methoxyquinone, amine compounds such as phenylenediamine and phenylhydrazine, and examples of the inorganic reducing agent include:
For example, sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, sulfite salts such as potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite,
Examples thereof include phosphites such as sodium dihydrogen phosphite and dipotassium hydrogen phosphite, hydrazine, sodium thiosulfate, and sodium dithionite.

The water-soluble or alkali-soluble reducing agent can be contained in the developing solution and the developing replenishing solution in an amount of 0.05 to 10% by weight.

The developer and the development replenisher may contain an organic acid carboxylic acid.

These organic acid carboxylic acids include aliphatic carboxylic acids having 6 to 20 carbon atoms, and aromatic carboxylic acids having a benzene ring or naphthalene ring substituted with a carboxyl group.

The fat-proof carboxylic acid has 6 to 20 carbon atoms.
Alkanoic acid is preferable, and specific examples thereof include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mistyric acid, palmitic acid, stearic acid and the like, and particularly preferable is carbon. Number 6
~ 12 alkanoic acids. Further, the fat-proof carboxylic acid is
It may be a fatty acid having a double bond in the carbon chain or a fatty acid having a branched carbon chain. The aliphatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

Specific examples of the aromatic carboxylic acid include benzoic acid, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, p-tert-butylbenzoic acid, o-aminobenzoic acid,
p-aminobenzoic acid, 2,4-dihydroxybenzoic acid,
2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-
Examples thereof include naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid and 2-naphthoic acid.

The aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

Aliphatic carboxylic acid and aromatic carboxylic acid are 0.
It can be included from 1 to 30% by weight.

The developer and development replenisher may contain the following anionic, nonionic and cationic surfactants.

As the anionic surfactant, higher alcohol (C ₆ -C ₂₂ ) sulfate ester salts [for example, sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, “Τeepol- 8
1 ”(trade name, manufactured by Shell Chemical Co., Ltd., secondary sodium alkyl sulfate, etc.), aliphatic alcohol phosphate salts (eg, cetyl alcohol phosphate sodium salt, etc.), alkylaryl sulfonates (eg, dodecylbenzene) Sulfonic acid sodium salt, isopropyl naphthalene sulfonic acid sodium salt, dinaphthalene disulfonic acid sodium salt, metanitrobenzene sulfonic acid sodium salt, etc., alkyl amide sulfonates (eg, C ₁₇ H ₃₃ CON)
(CH ₃ ) CH ₂ SO ₃ Na and the like, sulfonates of dibasic fatty acid ester (for example, dioctyl sodium sulfosuccinate, dihexyl sodium sulfosuccinate, etc.). Among these, sulfonates are particularly preferably used.

As the nonionic surfactant, both polyethylene glycol type and polyhydric alcohol type can be used.

Examples of the nonionic surfactant include, for example,
Examples thereof include compounds represented by the following general formulas [1] to [8].

[0085]

Embedded image In the general formulas [1] to [8], R is a hydrogen atom or 1
Represents a valent organic group, and a, b, c, m, n, x and y each represent an integer of 1 to 40.

Examples of the organic group represented by R include a linear or branched alkyl group having 1 to 30 carbon atoms, an alkyl group having a substituent [for example, an aryl group (phenyl etc.)], and an alkyl moiety. Straight or branched carbon number 1 to 30
And an phenyl group which may have a substituent (for example, a hydroxyl group, the above-mentioned alkyl group, etc.) and the like.

Specific examples of the nonionic surfactant are shown below.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether,
Polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene behenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene stearyl amine, polyoxyethylene oleyl amine, polyoxyethylene stearic acid amide, Polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene Glyceryl monostearate, polyoxyethylene propylene glycol monostearate, oxyethyl Oxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxypropylene adduct, glycerol monostearate, sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, etc. .

The weight average molecular weight of the nonionic surfactant is
The range of 300 to 10,000 is preferred. The concentration of the nonionic surfactant in the developer can be at least 0.001 to 10% by weight.

Cationic surfactants are roughly classified into amine type and quaternary ammonium salt type, and any of these can be used.

Examples of the amine type include polyoxyethylene alkyl amine, N-alkyl propylene amine, N
-Alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, long-chain amine oxide, alkyl imidazoline, 1-
Hydroxyethyl-2-alkylimidazoline, 1-acetylaminoethyl-2-alkylimidazoline, 2-
Alkyl-4-methyl-4-hydroxymethyloxazoline and the like can be mentioned.

Examples of the quaternary ammonium salt type include long-chain primary amine salt, alkyltrimethylammonium salt, dialkyldimethylethylammonium salt, alkyldimethylammonium salt, alkyldimethylbenzylammonium salt, alkylpyridinium salt, and alkylquinone. Norinium salt, alkylisoquinolinium salt, alkylpyridinium sulfate, stearamidomethylpyridinium salt, acylaminoethyldiethylamine salt, acylaminoethylmethyldiethylammonium salt, alkylamidopropyldimethylbenzylammonium salt, fatty acid polyethylene polyamide, acylamino Ethylpyridinium salt, Acylcholaminoformylmethylpyridinium salt, Stearooxymethylpyridinium salt, Fatty acid triethanolamine, Fat Acid triethanolamine formate, trioxyethylene fatty acid triethanolamine,
Examples thereof include fatty acid dibutylaminoethanol, cetyloxymethylpyridinium salt, and p-isooctylphenoxyethoxyethyldimethylbenzil ammonium salt. ("Alkyl" in the examples of the above compounds has 6 carbon atoms.
~ 20 straight chain or partially substituted alkyl,
Specifically, straight chain alkyl such as hexyl, octyl, cetyl, stearyl is preferably used. Further, a cationic surfactant of a polymer having a cation component as a repeating unit, for example, a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic monomer can be contained.

The amount of the cationic surfactant added to the developer may be at least 0.001 to 10% by weight.

The weight average molecular weight is at least 300-500.
The range of 00 can be used.

As the surfactant, it is preferable to use a fluorine-containing surfactant containing a perfluoroalkyl group in the molecule. As such a fluorine-based surfactant,
Perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, anion type such as perfluoroalkyl phosphate, amphoteric type such as perfluoroalkyl betaine, cation type such as perfluoroalkyltrimethylammonium salt and perfluoroalkylamine oxide, Perfluoroalkyl ethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, oligomer containing perfluoroalkyl group, hydrophilic group and lipophilic group, perfluoroalkyl group and parent A nonionic type such as an oily group-containing urethane may be mentioned.

The above surfactants can be used alone or in combination of two or more kinds.

The developer and the development replenisher may contain an organic solvent.

As the organic solvent, those having a solubility in water at 20 ° C. of not more than 10% by weight are preferable, and for example, ethyl acetate, propyl acetate, butyl acetate, benzyl acetate,
Ethylene glycol monobutyl acetate, butyl lactate,
Carboxylic acid esters such as butyl levulinate; Ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n Alcohols such as amyl alcohol, methyl amyl alcohol;
Alkyl-substituted aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as methylene dichloride, ethylene dichloride and monochlorobenzene.

These organic solvents can be used alone or in combination of two or more kinds.

Further, the following additives can be added to the developer and the development replenisher in order to enhance the developing performance. Examples of these additives include, for example, JP-A-58-75152.
Neutral salts such as NaCl, KCl and KBr described in JP-A-59-190952, chelating agents such as EDTA and NTA described in JP-A-59-190952, and [Co (N
H ₃ )] ₆ Cl _{3 and} other complexes, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, JP-A-58-59444 Inorganic lithium compounds such as lithium chloride described, organic lithium compounds such as lithium benzoate described in JP-B-50-34442, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, The organic boron compounds described in JP-A-59-84241 are mentioned.

Further, known additives can be added to the developer and the development replenisher.

[0102]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 [Preparation of Aluminum Plate] A 0.3 mm thick aluminum plate (material 1050, tempered H16) was degreased for 1 minute in a 5% sodium hydroxide aqueous solution kept at 65 ° C. After that, it was washed with water and immersed in a 10% sulfuric acid aqueous solution kept at 25 ° C for 1 minute,
It was neutralized and further washed with water. This aluminum plate was placed in a 1.0 wt% hydrochloric acid aqueous solution at a temperature of 25 ° C. and a current density of 100 A.
Electrolytic surface roughening was performed with an alternating current under the conditions of / dm ² and a treatment time of 60 seconds. Then in a 5% aqueous sodium hydroxide solution
Desmutting treatment was performed at 60 ° C. for 10 seconds, and then anodizing treatment was performed in a 20% sulfuric acid solution under the conditions of a temperature of 20 ° C., a current density of 3 A / dm ² , and a treatment time of 1 minute. Then, it was immersed in a 1% sodium nitrite aqueous solution kept at 80 ° C for 30 seconds, washed with water, and dried at 80 ° C for 3 minutes. Further, after immersing in an aqueous solution of carboxymethylcellulose (concentration: 0.1% by weight) kept at 85 ° C. for 30 seconds, it was dried at 80 ° C. for 5 minutes to prepare a support.

[Preparation of photosensitive lithographic printing plate sample] The above-mentioned photosensitive layer coating solution shown in Table 1 was applied onto the above support using a wire bar, and dried under the following drying conditions shown in Table 1,
Photosensitive planographic printing plate samples 1 to 3 were prepared. The film thickness of the photosensitive layer was 2.0 μm.

[0105]

[Table 1]

<Photosensitive layer coating liquid composition> (Photosensitive layer coating liquid A) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallol acetone resin ( Weight average molecular weight 3000) and o-naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2 , 4-bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g methyl ethyl ketone / Diethyl carbitol = 50/50 100 ml

(Photosensitive Layer Coating Solution B) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 0.2 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl ethyl ketone / diethyl carbitol = 50/50 100 ml

(Photosensitive Layer Coating Solution C) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 0.2 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl ethyl ketone / 2-methoxyethyl acetate = 4 / 100 ml

(Photosensitive Layer Coating Solution D) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl ethyl ketone / 2-methoxyethyl acetate = 4 / 100 ml

<Drying condition after coating photosensitive layer> (Drying condition A) Drying at 40 ° C for 1 minute (Drying condition B) Drying at 55 ° C for 1 minute (Drying condition C) Drying at 100 ° C for 1 minute

The sensitivity and printing durability of the obtained photosensitive lithographic printing plate sample were evaluated as follows. The obtained results are shown in Table 2.

<< Evaluation Method >> = Evaluation of Sensitivity = A step tablet for sensitivity measurement (No. 2, Eastman Kodak Co., Ltd., 21-step gray scale with 0.15 density difference) was closely attached to the sample, and a 4kW metal halide lamp (large) Exposure was performed from a distance of 90 cm using a Japanese screen vio Quick manufactured by Nihon Screen Co., Ltd. as a light source.

Next, this sample was developed at 27 ° C. for 20 seconds with a developer obtained by diluting SDR-1 (manufactured by Konica Corp.) developer 6 times with water.

The sensitivity was defined as the exposure time at which 3.0 steps of the step tablet was completely cleared.

= Evaluation of printing durability = A step tablet for sensitivity measurement (No. 2 manufactured by Eastman Kodak Co., 21 levels of gray scale with 0.15 density difference) was adhered to the sample, and a 4kW metal halide lamp (Dainippon Screen) was used. Exposure was carried out from a distance of 90 cm using vio Quick manufactured by Co., Ltd. as a light source.

Next, this sample was developed for 20 seconds at 27 ° C. with a developer obtained by diluting SDR-1 (manufactured by Konica Corp.) developer by 6 times with water.

The obtained lithographic printing plate was applied to a printing machine GTO manufactured by Heidelberg Co., Ltd., and coated paper, printing ink (New Bright Red manufactured by Toyo Ink Mfg. Co., Ltd.) and fountain solution (SEU-3 manufactured by Konica Corp.) 2.5%) is used for printing,
Printing was continued until defective solidification appeared in the solid portion of the image of the printed matter or ink became solid in the non-image area, and the number of printed sheets at that time was counted.

[0118]

[Table 2]

Further, the obtained photosensitive lithographic printing plate sample was
Grim glow surface analyzer JY 5 manufactured by Atago Bussan Co., Ltd.
Surface analysis was performed using 0S GDS, and Elem / Fi values of S atoms contained in the o-quinonediazide compound of the photosensitive layer and Al atoms contained in the support were measured as a function of time.
The obtained results are shown in FIGS. 1 and 2. Figure 1 shows sample 1
FIG. 2 shows the measurement results of Sample 3. The large Elem / Fi value of the S atom in FIGS. 1 and 2 indicates that the content of the o-quinonediazide compound on the surface at that time is large.

In FIG. 1 and FIG. 2, Elem / Fi of S atom
When the value and the Elem / Fi value of Al atom became equal, the photosensitive layer disappeared and the grain of the support appeared.

As shown in FIG. 1, in Sample 1, the content of the condensate of pyrogallolacetone resin and o-naphthoquinonediazide-5-sulfonyl chloride in the photosensitive layer is the highest on the surface of the photosensitive layer.

[0122]

INDUSTRIAL APPLICABILITY The photosensitive lithographic printing plate of the present invention has a wide range of suitable developing conditions, has sufficient printing durability without deterioration of film strength, and has sufficient sensitivity. .

[Brief description of drawings]

[Figure 1] Photosensitive lithographic printing plate sample Sample 1 is Atago Bussan Co., Ltd.
It is a graph which shows the result of having performed the surface analysis using the Grim glow surface analyzer JY50S GDS by a company.

[Fig. 2] Photosensitive planographic printing plate sample Sample 3 is Atago Bussan Co., Ltd.
It is a graph which shows the result of having performed the surface analysis using the Grim glow surface analyzer JY50S GDS by a company.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Company

Claims (4)

[Claims] 1. The maximum concentration of the o-quinonediazide compound on the support is 1/2 of the film thickness of the photosensitive layer when viewed from the support side.
A photosensitive lithographic printing plate comprising at least one photosensitive layer containing an o-quinonediazide compound and an alkali-soluble resin, which is located farther away. 2. The photosensitive lithographic printing plate according to claim 1, wherein the number of the photosensitive layers containing the o-quinonediazide compound and the alkali-soluble resin provided on the support is one. 3. A support comprising a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble resin as a good solvent for an o-quinonediazide compound having a low boiling point and a poor solvent for an o-quinonediazide compound having a high boiling point. The method for producing a photosensitive lithographic printing plate according to claim 1 or 2, wherein a coating solution dissolved in a mixed solvent is applied and dried under at least two or more different temperature conditions. 4. The method for producing a photosensitive lithographic printing plate as claimed in claim 3, wherein drying is carried out at a low temperature in the initial stage and then at a high temperature.